An Iraqi policeman tries on a gasmask at the Qayyarah military base, about 60 kilometres (35 miles) south of Mosul, on October 16, 2016, as they prepare for an offensive to retake Mosul, the last IS-held city in the country, after regaining much of the territory the jihadists seized in 2014 and 2015. (Photo by Ahmad Al-Rubaye/AFP Photo)
